Now, four months later, the mute blond virtuoso remains in a psychiatric hospital in Dartford. His carerssaid yesterday that they believe that he may never be identified.
He was taken to the Medway Maritime Hospital in Gillingham on 7 April and when staff gave him a pen and paper, he drew detailed pictures of a grand piano. When he was shown a piano in the hospital chapel, he played classical music "beautifully" for four hours.
Staff at the West Kent NHS Trust are still sifting through a list of more than 200 names provided during a welter of publicity about the case when it first became public in May.
Camera crews from Germany to Japan descended on bemused citizens of the Isle of Sheppey, where Piano Man was found, as news of the talented musician in a wet suit spread around the globe. But despite a number of promising leads, ranging from suggestions that Piano Man was a French street musician to a Czech concert pianist, nothing has come to light which has given the patient a nationality, let alone a name. A source at the West Kent trust said: "We have discounted a lot of the names and continue to look at those which remain. But there is no obvious lead - we haven't had someone bashing down the door saying, 'This is my son' or 'This is my brother'.
"Given the enormous amount of publicity about Piano Man we think it surprising that someone who knows him has not come forward.
"It is possible that his family lead an isolated existence and have not seen the stories but we have to prepare ourselves for the fact that we may never know who he is and that he may be with us for a long time."
The search for the identity of the slightly-built man is being conducted by the trust with the help of Scotland Yard and the National Missing Persons Helpline.
But in the absence of a definite claim from a family member, staff are having to rely on names provided by people identifying Piano Man as a school friend or acquaintance.
The team are also having to deal with calls from families claiming Piano Man as a long-disappeared relative. The source said: "We have had people saying he is a long-lost child or something on similar lines but sadly they are cases of hope rather than reality."
Psychiatrists do not know why the man, who continues to shrink from any stranger, has not spoken a word for four months. Diagnoses of his condition initially focused on post-traumatic stress disorder but it is now thought he may be an autistic savant. Sufferers of the condition can display extraordinary but highly specific talents, such as drawing or mathematics, while at the same time remaining withdrawn or uncommunicative to the point of remaining silent.
The removal of labels from clothing can also be associated with autism.
Officially the trust will not comment on the young man's treatment beyond saying that his physical health remains good. But it is understood he is showing increasing signs of rapport with a small number of trusted carers.
When Piano Man was found wandering in the dark beside the beach, he had not only cut the labels from the dark suit he was wearing but also rubbed any identifying marks from his shoes.
The sheer lack of any identifying signs along with Piano Man's inability to communicate has produced a succession of theories as to how he arrived on the Kent coast, from being a Norwegian sailor to a member of a visiting orchestra.
Staff at the Littlebrook Hospital are increasingly clinging on to the hope that Piano Man will himself give up his identity.
A spokesman said: "It may be that matters suddenly progress and the next thing we hear about Piano Man is that he has been returned to his family."